Axle assembly and shift mechanism for a shift collar

ABSTRACT

An adjuster mechanism and an axle assembly that includes an adjuster mechanism. The adjuster mechanism may include a collar assembly that has a collar that may receive a shift collar, a follower, and an adjustment screw. Rotating the adjustment screw may move the collar assembly and the shift collar along an axis.

TECHNICAL FIELD

This disclosure relates to a shift mechanism for a shift collar and anaxle assembly having a shift mechanism.

BACKGROUND

An axle assembly having a clutch collar is disclosed in U.S. Pat. No.9,719,563.

SUMMARY

In at least one embodiment a shift mechanism is provided. The shiftmechanism may include a shift collar, an actuator, and an adjustermechanism. The adjuster mechanism may include a collar assembly, afollower, and an adjustment screw. The collar assembly may include acollar and a shift block. The collar may define a collar hole that mayreceive the shift collar. The shift block may be fixedly positioned withrespect to the collar. The shift block may define an elongated slot anda first hole that extends from the elongated slot. The follower may bepartially received in the elongated slot and may be operativelyconnected to the actuator. The follower may define a threaded hole. Theadjustment screw may be received in the first hole and the threadedhole. The adjustment screw may be rotatable about an adjustment screwaxis. Rotating the adjustment screw may move the collar assembly and theshift collar along an axis.

In at least one embodiment an axle assembly is provided. The axleassembly may include a drive pinion, a transmission, and a shiftmechanism. The drive pinion may be rotatable about an axis. Thetransmission may include a set of drive pinion gears that may be spacedapart from the drive pinion and that may be rotatable about the axis.The shift mechanism may include a shift collar, an actuator, and anadjuster mechanism. The shift collar may be rotatable about the axiswith the drive pinion and may be movable along the axis with respect tothe drive pinion. The actuator may be configured to move the shiftcollar along the axis to selectively connect a member of the set ofdrive pinion gears to the drive pinion. The adjuster mechanism mayconnect the actuator to the shift collar. The adjuster mechanism mayinclude a collar assembly, a follower, and an adjustment screw. Thecollar assembly may include a collar and a shift block. The collar maydefine a collar hole that may receive the shift collar. The shift blockmay be fixedly positioned with respect to the collar. The shift blockmay define an elongated slot in a first hole that may extend from theelongated slot. The follower may be partially received in the elongatedslot and may be operatively connected to the actuator. The follower maydefine a threaded hole. The adjustment screw may be received in thefirst hole and the threaded hole. The adjustment screw may be rotatableabout an adjustment screw axis. Rotating the adjustment screw may movethe collar assembly with respect to the follower.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an example of an axle assembly.

FIG. 2 is a section view of the axle assembly along section line 2-2.

FIG. 3 is an end view of the axle assembly with a cover at the end ofthe axle assembly removed.

FIG. 4 is a perspective view that includes an example of a shiftmechanism that may be provided with the axle assembly and a firstconfiguration of a shift collar.

FIG. 5 is a section view of a portion of the axle assembly along sectionline 5-5 with a second configuration of a shift collar.

FIG. 6 is an exploded view of a portion of the shift mechanism and theshift collar shown in FIG. 5.

FIG. 7 is a section view of a portion of the axle assembly with theshift collar of FIG. 5 in a first position.

FIG. 8 is a section view of a portion of the axle assembly with theshift collar in a first neutral position.

FIG. 9 is a section view of a portion of the axle assembly with theshift collar in a second position.

FIG. 10 is a section view of a portion of the axle assembly with theshift collar in a second neutral position.

FIG. 11 is a section view of a portion of the axle assembly with theshift collar in a third position.

FIG. 12 is a perspective view of an example of an adjuster mechanismthat may be provided with the shift mechanism.

FIG. 13 is an exploded view of the adjuster mechanism shown in FIG. 12.

FIG. 14 is a magnified view of a portion of FIG. 7 that shows theadjuster mechanism in a nominal position.

FIG. 15 illustrates an example of the adjuster mechanism in an adjustedposition.

DETAILED DESCRIPTION

As required, detailed embodiments of the present invention are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention that may be embodied in variousand alternative forms. The figures are not necessarily to scale; somefeatures may be exaggerated or minimized to show details of particularcomponents. Therefore, specific structural and functional detailsdisclosed herein are not to be interpreted as limiting, but merely as arepresentative basis for teaching one skilled in the art to variouslyemploy the present invention.

Referring to FIG. 1, an example of an axle assembly 10 is shown. Theaxle assembly 10 may be provided with a motor vehicle like a truck, bus,farm equipment, mining equipment, military transport or weaponryvehicle, or cargo loading equipment for land, air, or marine vessels.The motor vehicle may include a trailer for transporting cargo in one ormore embodiments.

The axle assembly 10 may provide torque to one or more traction wheelassemblies that may include a tire mounted on a wheel. The wheel may bemounted to a wheel hub that may be rotatable about a wheel axis.

One or more axle assemblies may be provided with the vehicle. As is bestshown with reference to FIGS. 1 and 2, the axle assembly 10 may includea housing assembly 20, a differential assembly 22, at least one axleshaft 24, an electric motor module 26, and a transmission module 28, adrive pinion 30, a shift mechanism 32, or combinations thereof.

Housing Assembly

Referring to FIG. 1, the housing assembly 20 may receive variouscomponents of the axle assembly 10. In addition, the housing assembly 20may facilitate mounting of the axle assembly 10 to the vehicle. In atleast one configuration, the housing assembly 20 may include an axlehousing 40 and a differential carrier 42.

The axle housing 40 may receive and may support the axle shafts 24. Inat least one configuration, the axle housing 40 may include a centerportion 50 and at least one arm portion 52.

The center portion 50 may be disposed proximate the center of the axlehousing 40. As is best shown in FIG. 2, the center portion 50 may definea cavity 54 that may at least partially receive the differentialassembly 22. A lower region of the center portion 50 may at leastpartially define a sump portion 56 that may contain or collect lubricant58. Lubricant 58 in the sump portion 56 may be splashed by a ring gear82 of the differential assembly 22 and distributed to lubricate variouscomponents that may or may not be received in the housing assembly 20.For instance, some splashed lubricant 58 may lubricate components thatare received in the cavity 54 like the differential assembly 22, bearingassemblies that rotatably support the differential assembly 22, a drivepinion 30, and so on, while some splashed lubricant 58 may be routed outof the cavity 54 to lubricate components located outside of the housingassembly 20, such as components associated with the transmission module28, the shift mechanism 32, or both.

Referring to FIG. 1, one or more arm portions 52 may extend from thecenter portion 50. For instance, two arm portions 52 may extend inopposite directions from the center portion 50 and away from thedifferential assembly 22. The arm portions 52 may have similarconfigurations. For example, the arm portions 52 may each have a hollowtubular configuration that may extend around and may receive acorresponding axle shaft 24 and may help separate or isolate the axleshaft 24 or a portion thereof from the surrounding environment. An armportion 52 or a portion thereof may or may not be integrally formed withthe center portion 50. It is also contemplated that the arm portions 52may be omitted.

Referring primarily to FIG. 2, the differential carrier 42 may bemounted to the center portion 50 of the axle housing 40. Thedifferential carrier 42 may support the differential assembly 22 and mayfacilitate mounting of the electric motor module 26. For example, thedifferential carrier 42 may include one or more bearing supports thatmay support a bearing like a roller bearing assembly that may rotatablysupport the differential assembly 22. In at least one configuration, thedifferential carrier 42 may include a mounting flange 60 and/or abearing support wall 62.

The mounting flange 60 may facilitate mounting of the electric motormodule 26. As an example, the mounting flange 60 may be configured as aring that may extend around the axis 70. In at least one configuration,the mounting flange 60 may include a set of fastener holes that may beconfigured to receive fasteners that may secure the electric motormodule 26 to the mounting flange 60.

The bearing support wall 62 may support bearings that may rotatablysupport other components of the axle assembly 10. For example, thebearing support wall 62 may support a bearing that may rotatably supportthe drive pinion 30, a bearing that may rotatably support a rotor of theelectric motor module 26, or both. The bearing support wall 62 mayextend in an axial direction away from the axle housing 40 and mayextend around the axis 70. The bearing support wall 62 may define a holethat may extend along or around the axis 70 and receive the drive pinion30 and the bearings that rotatably support the drive pinion 30. Thebearing support wall 62 may be integrally formed with the differentialcarrier 42 or may be a separate component that is fastened to thedifferential carrier 42.

Differential Assembly, Drive Pinion, and Axle Shafts

Referring to FIG. 2, the differential assembly 22 may be at leastpartially received in the center portion 50 of the housing assembly 20.The differential assembly 22 may be rotatable about a differential axis80 and may transmit torque to the axle shafts 24 and wheels. Thedifferential assembly 22 may be operatively connected to the axle shafts24 and may permit the axle shafts 24 to rotate at different rotationalspeeds in a manner known by those skilled in the art. The differentialassembly 22 may have a ring gear 82 that may have teeth that mate ormesh with the teeth of a gear portion of a drive pinion 30. Accordingly,the differential assembly 22 may receive torque from the drive pinion 30via the ring gear 82 and transmit torque to the axle shafts 24.

The drive pinion 30 may operatively connect the transmission module 28to the differential assembly 22. As such, the drive pinion 30 maytransmit torque between the differential assembly 22 and thetransmission module 28. In at least one configuration, the drive pinion30 may be rotatable about the axis 70 and may be rotatably supportedinside another component, such as the bearing support wall 62.

Referring primarily to FIGS. 2 and 6, the drive pinion 30 may optionallyinclude or may be coupled to a drive pinion extension 90. The drivepinion extension 90 may increase the axial length of the drive pinion30. In at least one configuration, the drive pinion extension 90 may bea separate component from the drive pinion 30 and may be coupled to thedrive pinion 30 such that the drive pinion extension 90 is rotatableabout the axis 70 with the drive pinion 30. In addition, the drivepinion extension 90 may be fixedly positioned with respect to the drivepinion 30 such that the drive pinion extension 90 may not move along theaxis 70 with respect to the drive pinion 30. It is also contemplatedthat the drive pinion extension 90 may be integrally formed with thedrive pinion 30, in which case the drive pinion 30 may be a one-pieceunitary component having a greater axial length.

In at least one configuration, the drive pinion extension 90 may extendfrom a first end 92 to a second end 94 and may include a socket 96 andthe spline 98. The socket 96 may extend from the first end 92 and mayreceive the drive pinion 30. The second end 94 may be received insideand may be rotatably supported by a support bearing 418. The spline 98,if provided, may facilitate coupling of the drive pinion extension 90 toa shift collar 310 that may be moveable along the axis 70 as will bediscussed in more detail below.

Referring to FIG. 1, the axle shafts 24 may transmit torque from thedifferential assembly 22 to corresponding wheel hubs and wheels. Twoaxle shafts 24 may be provided such that each axle shaft 24 extendsthrough a different arm portion 52 of axle housing 40. The axle shafts24 may extend along and may be rotatable about an axis, such as thedifferential axis 80. Each axle shaft 24 may have a first end and asecond end. The first end may be operatively connected to thedifferential assembly 22. The second end may be disposed opposite thefirst end and may be operatively connected to a wheel. Optionally, gearreduction may be provided between an axle shaft 24 and a wheel.

Electric Motor Module

Referring to FIG. 2, the electric motor module 26, which may also bereferred to as an electric motor, may be mounted to the differentialcarrier 42 and may be operatively connectable to the differentialassembly 22. For instance, the electric motor module 26 may providetorque to the differential assembly 22 via the transmission module 28and the drive pinion 30 as will be discussed in more detail below. Theelectric motor module 26 may be primarily disposed outside thedifferential carrier 42. In addition, the electric motor module 26 maybe axially positioned between the axle housing 40 and the transmissionmodule 28. In at least one configuration, the electric motor module 26may include a motor housing 100, a coolant jacket 102, a stator 104, arotor 106, and at least one rotor bearing assembly 108. The electricmotor module 26 may also include a motor cover 110.

The motor housing 100 may extend between the differential carrier 42 andthe motor cover 110. The motor housing 100 may be mounted to thedifferential carrier 42 and the motor cover 110. For example, the motorhousing 100 may extend from the mounting flange 60 of the differentialcarrier 42 to the motor cover 110. The motor housing 100 may extendaround the axis 70 and may define a motor housing cavity 120. The motorhousing cavity 120 may be disposed inside the motor housing 100 and mayhave a generally cylindrical configuration. The bearing support wall 62of the differential carrier 42 may be located inside the motor housingcavity 120. Moreover, the motor housing 100 may extend continuouslyaround and may be spaced apart from the bearing support wall 62. In atleast one configuration, the motor housing 100 may have an exterior side122, an interior side 124, a first end surface 126, and a second endsurface 128.

The exterior side 122 may face away from the axis 70 and may define anexterior or outside surface of the motor housing 100.

The interior side 124 may be disposed opposite the exterior side 122 andmay face toward the axis 70. The interior side 124 may be disposed at asubstantially constant radial distance from the axis 70 in one or moreconfigurations.

The first end surface 126 may extend between the exterior side 122 andthe interior side 124. The first end surface 126 may be disposed at anend of the motor housing 100 that may face toward the differentialcarrier 42. For instance, the first end surface 126 may be disposedadjacent to the mounting flange 60 of the differential carrier 42 andmay engage or contact the mounting flange 60.

The second end surface 128 may be disposed opposite the first endsurface 126. As such, the second end surface 128 may be disposed at anend of the motor housing 100 that may face toward the motor cover 110and may engage or contact the motor cover 110.

The coolant jacket 102 may help cool or remove heat from the stator 104.The coolant jacket 102 may be received in the motor housing cavity 120of the motor housing 100 and may engage the interior side 124 of themotor housing 100. The coolant jacket 102 may extend axially (e.g., in adirection along the axis 70) between the differential carrier 42 and themotor cover 110. For example, the coolant jacket 102 may extend axiallyfrom the differential carrier 42 to the motor cover 110. In addition,the coolant jacket 102 may extend around the axis 70 and around thestator 104. Accordingly, the stator 104 may be at least partiallyreceived in and may be encircled by the coolant jacket 102. The coolantjacket 102 may extend in a radial direction from the stator 104 to theinterior side 124 of the motor housing 100. In at least oneconfiguration, the coolant jacket 102 may include a plurality ofchannels through which coolant may flow.

The stator 104 may be received in the motor housing cavity 120. Thestator 104 may be fixedly positioned with respect to the coolant jacket102. For example, the stator 104 may extend around the axis 70 and mayinclude stator windings that may be received inside and may be fixedlypositioned with respect to the coolant jacket 102.

The rotor 106 may extend around and may be rotatable about the axis 70.In addition, the rotor 106 may extend around and may be supported by thebearing support wall 62. The rotor 106 may be received inside the stator104, the coolant jacket 102, and the motor housing cavity 120 of themotor housing 100. The rotor 106 may be rotatable about the axis 70 withrespect to the differential carrier 42 and the stator 104. In addition,the rotor 106 may be spaced apart from the stator 104 but may bedisposed in close proximity to the stator 104.

One or more rotor bearing assemblies 108 may rotatably support the rotor106. For example, a rotor bearing assembly 108 may extend around andreceive the bearing support wall 62 of the differential carrier 42 andmay be received inside of the rotor 106. The rotor 106 may beoperatively connected to the drive pinion 30. For instance, a couplingsuch as a rotor output flange 130 may operatively connect the rotor 106to the transmission module 28, which in turn may be operativelyconnectable to the drive pinion 30.

The motor cover 110 may be mounted to the motor housing 100 and may bedisposed opposite the axle housing 40 and the differential carrier 42.For example, the motor cover 110 may be mounted to the second endsurface 128 of the motor housing 100. The motor cover 110 may be spacedapart from and may not engage the differential carrier 42. The motorcover 110 may be provided in various configurations. In at least oneconfiguration, the motor cover 110 may include a first side 140 and asecond side 142. The first side 140 may face toward and may engage themotor housing 100. The second side 142 may be disposed opposite thefirst side 140. The second side 142 may face away from the motor housing100. The motor cover 110 may also include a motor cover opening throughwhich the drive pinion 30 may extend. The motor cover 110 may beintegrated with the transmission module 28 or may be a separatecomponent.

Transmission Module

Referring to FIGS. 2 and 5, the transmission module 28 may transmittorque between the electric motor module 26 and the differentialassembly 22. As such, the transmission module 28 may be operativelyconnectable to the electric motor module 26 and the differentialassembly 22. In at least one configuration, the transmission module 28may include a first transmission housing 200, a second transmissionhousing 202, and a transmission 204. The first transmission housing 200and the second transmission housing 202 may cooperate to define atransmission housing cavity 206 that may receive the transmission 204.

The first transmission housing 200 may be mounted to the electric motormodule 26. For instance, the first transmission housing 200 may bemounted to the second side 142 of the motor cover 110. As such, themotor cover 110 may separate the first transmission housing 200 from themotor housing 100.

The second transmission housing 202 may be mounted to the firsttransmission housing 200. For instance, the first transmission housing200 may be mounted to and may engage or contact a side of the firsttransmission housing 200 that may face away from the motor cover 110. Assuch, the first transmission housing 200 may separate the secondtransmission housing 202 from the motor cover 110.

The transmission 204 may be operatively connected to the electric motor.In at least one configuration and as is best shown in FIG. 5, thetransmission 204 may be configured as a countershaft transmission thatmay include a set of drive pinion gears 210, a first countershaft gearset 212, and optionally a second countershaft gear set 214.

The set of drive pinion gears 210 may be received in the transmissionhousing cavity 206 and may be arranged along the axis 70 between thefirst transmission housing 200 and the second transmission housing 202.The set of drive pinion gears 210 may include a plurality of gears, someof which may be selectively coupled to the drive pinion 30. In theconfiguration shown, the set of drive pinion gears 210 includes a firstgear 220, a second gear 222, a third gear 224, and a fourth gear 226;however, it is to be understood that a greater or lesser number of gearsmay be provided.

The first gear 220 may extend around the axis 70 and may be disposedproximate the first transmission housing 200. In at least oneconfiguration, the first gear 220 may have a through hole that mayreceive the drive pinion 30, an extension of the drive pinion 30 likethe drive pinion extension 90, or both. The first gear 220 may have aplurality of teeth that may be arranged around and may extend away fromthe axis 70. The teeth of the first gear 220 may contact and may mate ormesh with teeth of a first countershaft gear that may be provided withthe first countershaft gear set 212 and the second countershaft gear set214 as will be discussed in more detail below. The first gear 220 may beoperatively connected to the rotor 106 of the electric motor module 26such that the rotor 106 and the first gear 220 are rotatable togetherabout the axis 70. For example, the first gear 220 may be fixedlypositioned with respect to the rotor 106 or fixedly coupled to the rotor106 such that the first gear 220 is not rotatable about the axis 70 withrespect to the rotor 106. It is contemplated that the first gear 220 maybe fixedly mounted to or integrally formed with the rotor output flange130. As such, the first gear 220 may be continuously connected to therotor 106 such that the first gear 220 and the rotor 106 may berotatable together about the axis 70 but may not be rotatable withrespect to each other. It is also contemplated that the first gear 220may be selectively coupled to the drive pinion 30 or drive pinionextension 90, such as with a shift collar. In addition, the first gear220 may be decoupled from the drive pinion 30 and may be rotatable withrespect to the drive pinion 30. As such, a clutch or shift collar 310may not connect the first gear 220 to the drive pinion 30 or the drivepinion extension 90. The drive pinion extension 90, if provided, may bereceived inside the first gear 220 and may be spaced apart from thefirst gear 220. In at least one configuration, the first gear 220 may beaxially positioned along the axis 70 between the second gear 222 and theelectric motor module 26.

Referring to FIGS. 5 and 7, the second gear 222 may extend around theaxis 70. In at least one configuration, the second gear 222 may have athrough hole that may receive the drive pinion 30, the drive pinionextension 90, or both. The second gear 222 may have a plurality of teeththat may be arranged around and may extend away from the axis 70. Theteeth of the second gear 222 may contact and may mate or mesh with teethof a second countershaft gear that may be provided with the firstcountershaft gear set 212 and the second countershaft gear set 214 aswill be discussed in more detail below. As is best shown in FIG. 7, thesecond gear 222 may also have inner gear teeth 232 that may extendtoward the axis 70 and may be received in the through hole. The secondgear 222 may have a different diameter than the first gear 220. Forexample, the second gear 222 may have a larger diameter than the firstgear 220 as is best shown in FIG. 5. In at least one configuration, thesecond gear 222 may be axially positioned along the axis 70 between thefirst gear 220 and the third gear 224. The drive pinion 30 or drivepinion extension 90, if provided, may be received inside the second gear222 and may be spaced apart from the second gear 222 in one or moreconfigurations.

Referring to FIGS. 5 and 7, the third gear 224 may extend around theaxis 70. In at least one configuration, the third gear 224 may have athrough hole that may receive the drive pinion 30, the drive pinionextension 90, or both. The third gear 224 may have a plurality of teeththat may be arranged around and may extend away from the axis 70. Theteeth of the third gear 224 may contact and may mate or mesh with teethof a third countershaft gear that may be provided with the firstcountershaft gear set 212 and the second countershaft gear set 214 aswill be discussed in more detail below. As is best shown in FIG. 7, thethird gear 224 may also have inner gear teeth 234 that may extend towardthe axis 70 and may be received in the through hole. The third gear 224may have a different diameter than the first gear 220 and the secondgear 222. For example, the third gear 224 may have a larger diameterthan the first gear 220 and the second gear 222 as is best shown in FIG.5. In at least one configuration, the third gear 224 be axiallypositioned along the axis 70 between the second gear 222 and the fourthgear 226. The drive pinion 30 or drive pinion extension 90, if provided,may be received inside the third gear 224 and may be spaced apart fromthe third gear 224 in one or more configurations.

Referring to FIGS. 5 and 7, the fourth gear 226 may extend around theaxis 70. In at least one configuration, the fourth gear 226 may have athrough hole that may receive the drive pinion 30, the drive pinionextension 90, or both. The fourth gear 226 may have a plurality of teeththat may be arranged around and may extend away from the axis 70. Theteeth of the fourth gear 226 may contact and may mate or mesh with teethof a fourth countershaft gear that may be provided with the firstcountershaft gear set 212 and the second countershaft gear set 214 aswill be discussed in more detail below. As is best shown in FIG. 7, thefourth gear 226 may also have inner gear teeth 236 that may extendtoward the axis 70 and may be received in the through hole. The fourthgear 226 may have a different diameter than the first gear 220, thesecond gear 222, and the third gear 224, such as a larger diameter. Inat least one configuration, the fourth gear 226 be axially positionedalong the axis 70 further from the electric motor module 26 than thefirst gear 220, the second gear 222, and the third gear 224. As such,the fourth gear 226 may be axially positioned proximate or adjacent to aside of the second transmission housing 202 that is disposed oppositethe first transmission housing 200. The drive pinion 30 or drive pinionextension 90 may be received inside the fourth gear 226 and may bespaced apart from the fourth gear 226 in one or more configurations.

Referring to FIG. 5, thrust bearings 240 may optionally be providedbetween members of the set of drive pinion gears 210, between the firsttransmission housing 200 and the set of drive pinion gears 210, betweenthe second transmission housing 202 and the set of drive pinion gears210, or combinations thereof. For instance, a first thrust bearing 240may be axially positioned between the first transmission housing 200 andthe first gear 220, a second thrust bearing 240 may be axiallypositioned between the first gear 220 and the second gear 222, a thirdthrust bearing 240 may be axially positioned between the second gear 222and the third gear 224, a fourth thrust bearing 240 may be axiallypositioned between the third gear 224 and the fourth gear 226, and afifth thrust bearing 240 may be axially positioned between the fourthgear 226 and the second transmission housing 202.

The first countershaft gear set 212 may be received in the transmissionhousing cavity 206 and may be in meshing engagement with the set ofdrive pinion gears 210. The first countershaft gear set 212 may berotatable about a first countershaft axis 250. The first countershaftaxis 250 may be disposed parallel or substantially parallel to the axis70 in one or more embodiments. The first countershaft gear set 212 mayinclude a first countershaft 260 and a plurality of gears. In theconfiguration shown, the plurality of gears of the first countershaftgear set 212 include a first countershaft gear 270, a secondcountershaft gear 272, a third countershaft gear 274, and a fourthcountershaft gear 276; however, it is contemplated that a greater numberof countershaft gears or a lesser number of countershaft gears may beprovided.

The first countershaft 260 may be rotatable about the first countershaftaxis 250. For instance, the first countershaft 260 may be rotatablysupported on the first transmission housing 200 and the secondtransmission housing 202 by corresponding bearing assemblies 280. Forexample, first and second bearing assemblies 280 may be located nearopposing first and second ends the first countershaft 260, respectively.The first countershaft 260 may support and be rotatable with the firstcountershaft gear 270, the second countershaft gear 272, the thirdcountershaft gear 274, and the fourth countershaft gear 276.

The first countershaft gear 270 may be fixedly disposed on the firstcountershaft 260 or fixedly mounted to the first countershaft 260. Assuch, the first countershaft gear 270 may rotate about the firstcountershaft axis 250 with the first countershaft 260 and may not berotatable with respect to the first countershaft 260. For example, thefirst countershaft gear 270 may have a hole that may receive the firstcountershaft 260 and may be fixedly coupled to the first countershaft260. The first countershaft gear 270 may extend around the firstcountershaft axis 250 and may have a plurality of teeth that may bearranged around and may extend away from the first countershaft axis250. The teeth of the first countershaft gear 270 may contact and maymate or mesh with the teeth of the first gear 220. In at least oneconfiguration, the first countershaft gear 270 may be axially positionedalong the first countershaft axis 250 between the first transmissionhousing 200 and the second countershaft gear 272 of the firstcountershaft gear set 212.

The second countershaft gear 272 may be fixedly disposed on the firstcountershaft 260 or fixedly mounted to the first countershaft 260. Assuch, the second countershaft gear 272 may rotate about the firstcountershaft axis 250 with the first countershaft 260 and may not berotatable with respect to the first countershaft 260. For example, thesecond countershaft gear 272 may have a hole that may receive the firstcountershaft 260 and may be fixedly coupled to the first countershaft260. The second countershaft gear 272 may extend around the firstcountershaft axis 250 and may have a plurality of teeth that may bearranged around and may extend away from the first countershaft axis250. The teeth of the second countershaft gear 272 may contact and maymate or mesh with the teeth of the second gear 222. The secondcountershaft gear 272 may have a different diameter than the firstcountershaft gear 270 and the third countershaft gear 274. In at leastone configuration, the second countershaft gear 272 may be axiallypositioned along the first countershaft axis 250 between the firstcountershaft gear 270 of the first countershaft gear set 212 and thethird countershaft gear 274 of the first countershaft gear set 212.

The third countershaft gear 274 may be fixedly disposed on the firstcountershaft 260 or fixedly mounted to the first countershaft 260. Assuch, the third countershaft gear 274 may rotate about the firstcountershaft axis 250 with the first countershaft 260 and may not berotatable with respect to the first countershaft 260. For example, thethird countershaft gear 274 may have a hole that may receive the firstcountershaft 260 and may be fixedly coupled to the first countershaft260. The third countershaft gear 274 may extend around the firstcountershaft axis 250 and may have a plurality of teeth that may bearranged around and may extend away from the first countershaft axis250. The teeth of the third countershaft gear 274 may contact and maymate or mesh with the teeth of the third gear 224. The thirdcountershaft gear 274 may have a different diameter than the firstcountershaft gear 270 and the second countershaft gear 272. In at leastone configuration, the third countershaft gear 274 may be axiallypositioned along the first countershaft axis 250 between the secondcountershaft gear 272 of the first countershaft gear set 212 and thefourth countershaft gear 276 of the first countershaft gear set 212.

The fourth countershaft gear 276 may be fixedly disposed on the firstcountershaft 260 or fixedly mounted to the first countershaft 260. Assuch, the fourth countershaft gear 276 may rotate about the firstcountershaft axis 250 with the first countershaft 260 and may not berotatable with respect to the first countershaft 260. For example, thefourth countershaft gear 276 may have a hole that may receive the firstcountershaft 260 and may be fixedly coupled to the first countershaft260 or may be integrally formed with the first countershaft 260. Thefourth countershaft gear 276 may extend around the first countershaftaxis 250 and may have a plurality of teeth that may be arranged aroundand may extend away from the first countershaft axis 250. The teeth ofthe fourth countershaft gear 276 may contact and may mate or mesh withthe teeth of the fourth gear 226. The fourth countershaft gear 276 mayhave a different diameter than the first countershaft gear 270, thesecond countershaft gear 272, and the third countershaft gear 274. In atleast one configuration, the fourth countershaft gear 276 may be axiallypositioned along the first countershaft axis 250 further from theelectric motor module 26 than the third countershaft gear 274 of thefirst countershaft gear set 212.

The second countershaft gear set 214, if provided, may be received inthe transmission housing cavity 206 and may be rotatable about a secondcountershaft axis 250′. The second countershaft axis 250′ may bedisposed parallel or substantially parallel to the axis 70 and the firstcountershaft axis 250 in one or more embodiments. The secondcountershaft gear set 214 may generally be disposed on an opposite sideof the axis 70 from the first countershaft gear set 212 or may bedisposed such that the first countershaft axis 250 and the secondcountershaft axis 250′ may be disposed at a common radial distance fromthe axis 70. The first and second countershaft gear sets 212, 214 may bepositioned at any suitable rotational angle or position about the axis70.

The second countershaft gear set 214 may have the same or substantiallythe same configuration as the first countershaft gear set 212. Forexample, the second countershaft gear set 214 may include a secondcountershaft 260′ that may be analogous to or may have the samestructure as the first countershaft 260. In addition, the secondcountershaft gear set 214 may include a plurality of gears that arerotatable with the second countershaft 260′. In the configuration shown,the plurality of gears of the second countershaft gear set 214 include afirst countershaft gear 270′, a second countershaft gear 272′, a thirdcountershaft gear 274′, and a fourth countershaft gear 276′; however, itis contemplated that a greater number of gears or a lesser number ofgears may be provided. The first countershaft gear 270′, secondcountershaft gear 272′, third countershaft gear 274′, and the fourthcountershaft gear 276′ of the second countershaft gear set 214 may beanalogous to or may have the same structure as the first countershaftgear 270, second countershaft gear 272, third countershaft gear 274, andthe fourth countershaft gear 276, respectively, of the firstcountershaft gear set 212. The first countershaft gear 270′, secondcountershaft gear 272′, third countershaft gear 274′, and the fourthcountershaft gear 276′ may be arranged along and may be rotatable abouta second countershaft axis 250′ rather than the first countershaft axis250 and may be fixed to the second countershaft 260′ rather than thefirst countershaft 260.

The first gear 220 and the first countershaft gears 270, 270′ mayprovide a different gear ratio than the second gear 222 and the secondcountershaft gears 272, 272′, the third gear 224 and the thirdcountershaft gears 274, 274′, and the fourth gear 226 and the fourthcountershaft gears 276, 276′. Gear ratios may be provided that aregreater than 1:1, less than 1:1, equal (i.e., 1:1), or combinationsthereof.

The teeth of the drive pinion gears and the countershaft gears may be ofany suitable type. As a non-limiting example, the meshing teeth of themembers of the set of drive pinion gears 210, the gears of the firstcountershaft gear set 212, and the gears of the second countershaft gearset 214 may have a helical configuration.

Shift Mechanism

Referring primarily to FIGS. 2-4, the shift mechanism 32 may selectivelyconnect the transmission module 28 and the drive pinion 30. For example,the shift mechanism 32 may operatively connect a member of the set ofdrive pinion gears 210 to the drive pinion 30 to provide torque at adesired gear ratio, and hence may change the torque transmitted betweenthe electric motor module 26 and the differential assembly 22. The shiftmechanism 32 may couple one member of the set of drive pinion gears 210at a time to the drive pinion 30. The member of the set of drive piniongears 210 that is coupled to the drive pinion 30 may be rotatable aboutthe axis 70 with the drive pinion 30.

The shift mechanism 32 may be received in or partially received in ashift mechanism housing cavity 300, which is best shown in FIGS. 2 and3. The shift mechanism housing cavity 300 may be partially defined bythe second transmission housing 202 and may be disposed proximate an endof the axle assembly 10. Referring to FIGS. 1 and 2, a cover 302 may bemounted on the end of the second transmission housing 202 to helpenclose the shift mechanism housing cavity 300. The cover 302 is removedin FIG. 3.

The shift mechanism 32 may have any suitable configuration. In at leastone configuration such as is shown in FIGS. 4 and 6, the shift mechanism32 may include a shift collar 310, an actuator 312, a detent linkage314, a linkage 316, and an adjuster mechanism 318.

The shift collar 310 may be rotatable about the axis 70 with the drivepinion 30. In addition, the shift collar 310 may be moveable along theaxis 70 with respect to the drive pinion 30. The shift collar 310 mayselectively connect a member of the set of drive pinion gears 210 to thedrive pinion 30 as will be discussed in more detail below. The shiftcollar 310 may be at least partially received in the shift mechanismhousing cavity 300 and may be extendable through components of thetransmission 204, such as the set of drive pinion gears 210. In at leastone configuration, the shift collar 310 may include a first end 320, asecond end 322, a shift collar hole 324, and a shift collar spline 326.The shift collar 310 may also include a first tubular shift collarportion 330, a second tubular shift collar portion 332, a first shiftcollar gear 334, a second shift collar gear 336, a threaded portion 338or combinations thereof.

The first end 320 may face toward the drive pinion 30. In addition, thefirst end 320 may be disposed adjacent to the drive pinion 30 or thedrive pinion extension 90.

The second end 322 may be disposed opposite the first end 320. As such,the second end 322 may face away from the drive pinion 30.

The shift collar hole 324 may extend along the axis 70 between the firstend 320 and the second end 322. In at least one configuration, the shiftcollar hole 324 may be configured as a through hole that may extend fromthe first end 320 to the second end 322. The drive pinion 30 or thedrive pinion extension 90 may be received inside the shift collar hole324.

The shift collar spline 326 may couple the shift collar 310 to the drivepinion 30 or the drive pinion extension 90. The shift collar spline 326may be disposed in the shift collar hole 324 and may be axiallypositioned near the first end 320. The shift collar spline 326 mayextend toward the axis 70 and may mate with a spline of the drive pinion30 or the spline 98 of the drive pinion extension 90 that may havespline teeth that may extend away from the axis 70. The mating splinesmay allow the shift collar 310 to move in an axial direction or alongthe axis 70 while inhibiting rotation of the shift collar 310 about theaxis 70 with respect to the drive pinion 30. Thus, the shift collar 310may be rotatable about the axis 70 with the drive pinion 30 when theshift collar spline 326 mates with the spline of the drive pinion 30 orthe drive pinion extension 90.

The first tubular shift collar portion 330 may extend from the first end320 toward the second end 322. The first tubular shift collar portion330 may have a hollow tubular configuration and may be at leastpartially received inside the set of drive pinion gears 210 of thetransmission 204. The first tubular shift collar portion 330 may have alarger outside diameter than the second tubular shift collar portion332.

The second tubular shift collar portion 332, if provided, may extendfrom the second end 322 toward the first tubular shift collar portion330 or to the first tubular shift collar portion 330. For instance, thesecond tubular shift collar portion 332 may have a hollow tubularconfiguration and may be at least partially disposed outside of the setof drive pinion gears 210.

The first shift collar gear 334 may be disposed between the first end320 and the second end 322 of the shift collar 310. In at least oneconfiguration, the first shift collar gear 334 may be disposed oppositethe shift collar hole 324 and may extend from the first tubular shiftcollar portion 330. The first shift collar gear 334 may have teeth thatmay be arranged around the axis 70 and that may extend away from theaxis 70 and away from the shift collar hole 324. The shift collar spline326 may be disposed opposite the first shift collar gear 334. It isnoted that an example of a shift collar 310 that has a first shiftcollar gear 334 but not a second shift collar gear 336 is shown in FIGS.2 and 4 while an example of a shift collar 310 that has a first shiftcollar gear 334 and a second shift collar gear 336 is shown in FIGS.5-11.

Referring to FIG. 6, the second shift collar gear 336, if provided, maybe spaced apart from the first shift collar gear 334. The second shiftcollar gear 336 may be axially positioned between the first end 320 andthe second end 322. For instance, the second shift collar gear 336 maybe axially positioned between the first shift collar gear 334 and thesecond tubular shift collar portion 332. In at least one configuration,the second shift collar gear 336 may be disposed opposite the shiftcollar hole 324 and may extend from the first tubular shift collarportion 330. The second shift collar gear 336 may have teeth that may bearranged around the axis 70 and that may extend away from the axis 70and away from the shift collar hole 324. The second shift collar gear336 may have a similar configuration as the first shift collar gear 334or a different configuration. For instance, the teeth of the secondshift collar gear 336 may have a greater axial length than the teeth ofthe first shift collar gear 334 to increase torque transmissioncapacity, reduce shift execution time, or both as will be discussed inmore detail below. The shift collar spline 326 may not be disposedopposite the second shift collar gear 336 in one or more embodiments.

The threaded portion 338 may be axially positioned between the first end320 and the second end 322. For instance, the threaded portion 338 maybe provided with the second tubular shift collar portion 332 and may beaxially positioned between the first tubular shift collar portion 330and the second end 322. The threaded portion 338 may be disposed on anexterior side of the second tubular shift collar portion 332 that mayface away from the axis 70. It is also contemplated that the threadedportion 338 may be omitted.

Referring to FIGS. 3 and 4, the actuator 312 may be configured to movethe shift collar 310 along the axis 70 to selectively connect a memberof the set of drive pinion gears 210 to the drive pinion 30. Theactuator 312 may be of any suitable type, such as an electrical,electromechanical, or mechanical actuator. In at least oneconfiguration, the actuator 312 may be mounted to the secondtransmission housing 202. A portion of the actuator 312 may be rotatableabout an actuator axis 350. For instance, the actuator 312 may have anactuator shaft that may extend along the actuator axis 350 and may berotatable about the actuator axis 350. The actuator shaft may beoperatively connected to the detent linkage 314.

Referring to FIG. 4, the detent linkage 314 may be fixedly coupled tothe actuator 312. For instance, the detent linkage 314 may be coupled tothe actuator shaft and may be rotatable about the actuator axis 350 withthe actuator shaft. The detent linkage 314 may define a plurality ofrecesses 360. The recesses 360 may be configured to receive a detentfeature 362. The detent feature 362 may inhibit rotation of the detentlinkage 314 about the actuator axis 350 when the detent feature 362 isreceived in a recess 360. For example, rotation of the detent linkage314 may be inhibited when the detent feature 362 is in a recess 360 anda sufficient actuation force is not provided by the actuator 312 toovercome the rotational resistance exerted by the detent feature 362.The detent linkage 314 may also be fixedly positioned with respect tothe linkage 316. As such, the detent feature 362 may inhibit movement ofthe linkage 316.

The linkage 316 may operatively connect the actuator 312 to the shiftcollar 310 and the adjuster mechanism 318. In at least oneconfiguration, the linkage 316 may be positioned along the actuator axis350 closer to the actuator 312 than the detent linkage 314 is positionedto the actuator 312. The linkage 316 may be coupled to the actuator 312and the detent linkage 314 such that the linkage 316 may be rotatableabout the actuator axis 350 with the actuator shaft and the detentlinkage 314. For example, the linkage 316 may be coupled to the detentlinkage 314 with one or more fasteners 370, such as pins or bolts. It isalso contemplated that the detent linkage 314 and the linkage 316 may beintegrally formed. In at least one configuration, the linkage 316 mayinclude an opening 372 that may facilitate coupling of the linkage 316to the adjuster mechanism 318.

Referring to FIGS. 6, 12 and 13, the adjuster mechanism 318 may connectthe linkage 316 to the shift collar 310. In addition, the adjustermechanism 318 may allow the axial position of the shift collar 310 to beadjusted independent of operation of the actuator 312 or withoutrotating the components of the shift mechanism 32 like the actuatorshaft, detent linkage 314, and linkage 316 about the actuator axis 350.In at least one configuration, the adjuster mechanism 318 may include acollar assembly 400, a follower 402, and an adjustment screw 404. Theadjuster mechanism 318 may also include a locking screw 406 and aretainer 408. As is best shown in FIG. 6, a first thrust bearing 410, asecond thrust bearing 412, a retainer nut 414, or combinations thereofmay optionally be associated with or disposed adjacent to the adjustermechanism 318. It is also contemplated that the adjuster mechanism 318may be omitted or reconfigured to omit components such as the adjustmentscrew 404, locking screw 406, and retainer 408. For instance, the collarassembly 400 may be provided with a collar 420 and a shift block 422that may be separate components that may be fastened together such thatspacers or shims may be provided between the collar 420 and shift block422 to adjust the axial positioning of the shift collar 310. It is alsocontemplated that the adjuster mechanism 318 may be provided with otherconfigurations, such as when a shift fork is used to operatively connecta shift collar to an actuator.

The collar assembly 400 may receive the shift collar 310. In at leastone configuration, the collar assembly 400 may include a collar 420 anda shift block 422.

The collar 420 may extend at least partially around the axis 70 in theshift collar 310. For instance, the collar 420 may be configured as aring that may extend around the axis 70. In at least one configuration,the collar 420 may include a first collar side 440, a second collar side442, and a collar hole 444.

The first collar side 440 may face toward the transmission module 28,the drive pinion 30, or both.

The second collar side 442 may be disposed opposite the first collarside 440. As such, the second collar side 442 may face away from thetransmission module 28, the drive pinion 30, or both.

The collar hole 444 may extend between the first collar side 440 and thesecond collar side 442. The collar hole 444 may be a through hole thatmay extend through the collar 420. The shift collar 310 may be receivedinside the collar hole 444 and may be rotatable about the axis 70 withrespect to the collar 420. For instance, the second tubular shift collarportion 332 may be received inside the collar hole 444 and may extendthrough the collar hole 444. In at least one configuration, the collarhole 444 may receive a bearing assembly that may be positioned betweenthe shift collar 310 and the collar 420. For example, the bearingassembly may extend from an outside circumference of the second tubularshift collar portion 332 to the inside diameter of the collar 420 thatdefines the collar hole 444.

The shift block 422 may be fixedly positioned with respect to the collar420. The shift block 422 may be integrally formed with the collar 420 ormay be provided as a separate component that is attached to the collar420. For instance, the shift block 422 may extend from an outsidecircumference of the collar 420, the second collar side 442, orcombinations thereof. In at least one configuration and as is best shownin FIGS. 12 and 13, the shift block 422 may define an elongated slot 470and a first hole 472. The shift block 422 may also define a second hole474, at least one locking screw hole 476, or combinations thereof.

The elongated slot 470 may be open in at least a direction that extendsaway from the axis 70. The elongated slot 470 may receive the follower402 with a clearance fit and may be configured to allow the collarassembly 400 to move in an axial direction or along the axis 70 withrespect to the follower 402. The elongated slot 470 may be longer in adirection that may extend parallel to the axis 70. In at least oneconfiguration, the elongated slot 470 may have a major axis 480 and aminor axis 482.

The major axis 480 may extend parallel or substantially parallel to theaxis 70. For instance, the major axis 480 may extend from the first hole472 toward or to the second hole 474. The major axis 480 may have agreater length than the minor axis 482. As such, the elongated slot 470may extend a greater distance along the major axis 480 than along theminor axis 482.

The minor axis 482 may be disposed substantially perpendicular to themajor axis 480. For instance, the minor axis 482 may extend in asubstantially vertical direction from the perspective shown.

The first hole 472 may extend from the elongated slot 470. In at leastone configuration, the first hole 472 may be a through hole that mayextend through the shift block 422 from the elongated slot 470 to anexterior surface of the shift block 422. In at least one configuration,the first hole 472 may not be threaded and may extend substantiallyparallel to the major axis 480 of the elongated slot 470 and may becoaxially disposed with the major axis 480 of the elongated slot 470.

The second hole 474, if provided, may be coaxially disposed with thefirst hole 472. In the configuration shown, the second hole 474 isdisposed closer to the shift collar 310 than the first hole 472;however, it is contemplated that the positioning of the first hole 472and the second hole 474 may be reversed. The second hole 474 may extendfrom the elongated slot 470. In at least one configuration, the secondhole 474 may be a through hole that may extend through the shift block422 from the elongated slot 470 to an exterior surface of the shiftblock 422 that may be disposed opposite the first hole 472. In at leastone configuration, the second hole 474 may not be threaded and may becoaxially disposed with the first hole 472. The second hole 474 mayextend substantially parallel to the major axis 480 of the elongatedslot 470 and may be coaxially disposed with the major axis 480 of theelongated slot 470. In at least one configuration, the second hole 474may have a smaller diameter than the first hole 472. Alternatively, thesecond hole 474 may have the same diameter or a larger diameter than thefirst hole 472.

One or more locking screw holes 476 may be spaced apart from the firsthole 472, the second hole 474, or both. In the configuration shown, thelocking screw hole 476 is disposed proximate the first hole 472 and isspaced apart from the first hole 472. The locking screw hole 476 mayreceive the locking screw 406. In at least one configuration, thelocking screw hole 476 may be a blind hole, a threaded hole, or both.

The follower 402 may connect or couple the linkage 316 to the collarassembly 400. As such, the follower 402 may help operatively connect theactuator 312 to the collar assembly 400. In at least one embodiment, thefollower 402 may be configured as a generally cylindrical pin that mayextend along a follower axis 490. The follower axis 490 may be disposedsubstantially perpendicular to the axis 70 and substantiallyperpendicular to the major axis 480 of the elongated slot 470. A portionof the follower 402 may be received in the opening 372 of the linkage316 and another portion of the follower 402 may be received in theelongated slot 470. The follower 402 may be sized to fit within theelongated slot 470 such that the follower 402 may be moveable in theelongated slot 470 along the major axis 480. For instance, the follower402 may have a width or diameter that may be less than the length of themajor axis 480 of the elongated slot 470, the minor axis 482 of theelongated slot 470, or both. In at least one configuration, the follower402 may define a threaded hole 492. The threaded hole 492 may bereceived in the elongated slot 470 and may be configured to receive theadjustment screw 404.

The adjustment screw 404 may couple the collar assembly 400 to thefollower 402. For instance, the adjustment screw 404 may be received inthe first hole 472 of the shift block 422 and the threaded hole 492 ofthe follower 402. The adjustment screw 404 may also be receivable in thesecond hole 474 of the shift block 422 if a second hole 474 is provided.The adjustment screw 404 may be rotatable about an adjustment screw axis500, which may be disposed substantially parallel to and may be coaxialwith the major axis 480 of the elongated slot 470. In at least oneconfiguration and as is best shown in FIG. 13, the adjustment screw 404may include a head 510, a threaded portion 512, a first shank portion514, a second shank portion 516, or combinations thereof.

The head 510 may be disposed proximate an end of the adjustment screw404. For instance, the head 510 may be disposed adjacent to the firsthole 472 of the shift block 422 and may be disposed outside of the firsthole 472. The head 510 may extend away from the axis 70 and may protrudefrom the first shank portion 514. In at least one configuration, thehead 510 may include a plurality of teeth 520. The teeth 520 may bearranged around the adjustment screw axis 500 and may extend away fromthe adjustment screw axis 500. A recess or gap 522 may be providedbetween adjacent teeth 520. For clarity, only some of the gaps arelabeled in FIG. 13.

The threaded portion 512 may be positioned along the adjustment screwaxis 500 between the head 510 and a distal end of the adjustment screw404. The threaded portion 512 may be received in the elongated slot 470.The threaded portion 512 may also be received in the threaded hole 492in the follower 402.

The first shank portion 514 may extend between the head 510 and thethreaded portion 512. The first shank portion 514 may be received in thefirst hole 472 of the shift block 422. The first shank portion 514 maybe rotatable in the first hole 472 and may or may not be threaded.

The second shank portion 516, if provided, may extend between thethreaded portion 512 and the distal end of the adjustment screw 404 thatis disposed opposite the head 510. The second shank portion 516 may bereceived in the second hole 474 of the shift block 422. The second shankportion 516 may be rotatable in the second hole 474. In at least oneconfiguration, the second shank portion 516 may protrude out of thesecond hole 474 and may include a groove or indentation 530 that mayreceive the retainer 408. Optionally, the second shank portion 516 mayhave a different diameter than the first shank portion 514, such as asmaller diameter, and may be threaded or unthreaded. It is alsocontemplated that the second shank portion 516 may be omitted, such aswhen the second hole 474 is not provided.

The locking screw 406 may inhibit rotation of the adjustment screw 404.For instance, the locking screw 406 may be partially received in thelocking screw hole 476 of the shift block 422. A portion of the lockingscrew 406 that protrudes from and may not be received in the lockingscrew hole 476 may engage the adjustment screw 404. For example, thehead of the locking screw 406 may engage the head 510 of the adjustmentscrew 404 and may be received in a gap 522 between adjacent teeth 520 ofthe head 510. As such, the locking screw 406 may engage the teeth 520that are disposed adjacent to the gap 522 in which the locking screw 406is received, thereby inhibiting rotation of the adjustment screw 404.

The retainer 408 may limit axial movement of the adjustment screw 404along the adjustment screw axis 500. The retainer 408 may inhibitremoval of the adjustment screw 404 from the shift block 422. Theretainer 408 may have any suitable configuration. For example, theretainer 408 may be configured as a fastener such as a snap ring, suchscrew, retaining pin, washer, or the like. In at least oneconfiguration, the retainer 408 may be mounted to the second shankportion 516 proximate the distal end of the adjustment screw 404. Forinstance, the retainer 408 may be received in the indentation 530 in thesecond shank portion 516 and may be disposed outside of the second hole474.

Referring to FIG. 6, the first thrust bearing 410 may facilitaterotation of the shift collar 310 about the axis 70 with respect to thecollar assembly 400. The first thrust bearing 410 may be axiallypositioned between the first collar side 440 and the shift collar 310.Optionally, washers may be axially positioned adjacent to one or bothsides of the first thrust bearing 410.

The second thrust bearing 412 may facilitate rotation of the shiftcollar 310 about the axis 70 with respect to the collar assembly 400.The second thrust bearing 412 may be positioned between the secondcollar side 442 and the retainer nut 414. Optionally a washer may beaxially positioned adjacent to one or both sides of the first thrustbearing 410. For example, a washer may be provided between the secondthrust bearing 412 and the retainer nut 414.

The retainer nut 414 may be mounted to the shift collar 310. Forinstance, the retainer nut 414 may have a threaded hole that may receivethe second tubular shift collar portion 332 and mate with the threadedportion 338 of the shift collar 310. The retainer nut 414 may inhibitaxial movement of the shift collar 310 with respect to the collar 420and may help secure the first thrust bearing 410 and the second thrustbearing 412. It is also contemplated that the retainer nut 414 may beomitted and a different fastener or fastening technique may be used. Forinstance, a fastener like a snap ring or a press-fit fastener mayreplace a threaded connection.

An encoder disc 416 may optionally be mounted to the drive pinion 30 orthe drive pinion extension 90. In at least one configuration, theencoder disc 416 may be disposed adjacent to the retainer nut 414. Forinstance, the encoder disc 416 may be axially positioned between theretainer nut 414 and a support bearing 418 that rotatably supports thedrive pinion 30 or drive pinion extension 90. For example, the supportbearing 418 may be positioned between a shoulder of the drive pinion 30or drive pinion extension 90 and the support bearing 418, if provided.The encoder disc 416 may have detectable features such as protrusionsand/or recesses that may be detectable by a sensor to detect rotation orthe rotational speed of the drive pinion 30.

The support bearing 418 may rotatably support the drive pinion 30 ordrive pinion extension 90. For instance, the drive pinion 30 or drivepinion extension 90 may be received inside and may be rotatablysupported by the support bearing 418, which in turn may be supported bythe second transmission housing 202, the cover 302, or both.

Operation of the Adjuster Mechanism

The adjuster mechanism 318 may allow the shift collar 310 and the collarassembly 400 to be moved along the axis 70 to more precisely positionthe shift collar 310 with respect to the set of drive pinion gears 210and their inner gear teeth. As such, the adjuster mechanism 318 maycompensate for design tolerances, such as design tolerances that may beassociated with the axial positioning of the drive pinion gears 210, thedetent linkage 314, linkage 316, shimming of the thrust bearings 240, orcombinations thereof. Axial alignment of the gear portion or gearportions of the shift collar 310 and the inner gear teeth of the set ofdrive pinion gears 210 may be adjusted, which may improve gearengagement and shifting accuracy when the shift collar 310 is shiftedwith the actuator 312. Proper axial adjustment may inhibit collarkick-out or help ensure that teeth of a gear portion or gear portions ofthe shift collar 310 remain engaged with a drive pinion gear and mayhelp reduce tooth flank wear, including when teeth flanks have crownedprofiles (e.g., mating concave and convex flanks). Axial adjustment ofthe shift collar 310 may also help properly position the shift collar310 in a neutral position to help ensure that the shift collar 310 doesnot engage a member of the set of drive pinion gears 210. Suchdisengagement may help ensure that a spline of the shift collar 310 doesnot contact the spline of a drive pinion gear during synchronization andmay help avoid spline damage. An example of how the adjuster mechanism318 may be operated is as follows.

First, the detent feature 362, which is best shown in FIG. 4, may lockthe detent linkage 314 so that the detent linkage 314 may be inhibitedfrom rotating about the actuator axis 350 and so that the linkage 316 isheld in a stationary position. The linkage 316 may then inhibit movementof the follower 402.

Next, the locking screw 406 may be disengaged from the adjustment screw404. For instance, the locking screw 406 may be rotated to disengage thelocking screw 406 from the head 510 of the adjustment screw 404.

Next, the adjustment screw 404 may be rotated about the adjustment screwaxis 500. Rotating the adjustment screw 404 may cause the collarassembly 400 and the shift collar 310 to move along the axis 70 withrespect to the follower 402. An example of such movement is shown bycomparing FIG. 14 with FIG. 15. In FIG. 14, the collar assembly 400 isshown in a nominal position in which the follower 402 is generallycentered in the elongated slot 470. Rotating the adjustment screw 404 ina first direction about the adjustment screw axis 500 may loosen theadjustment screw 404 with respect to the follower 402, thereby actuatingthe collar assembly 400 and the shift collar 310 along the axis 70toward the cover 302, or to the right from the perspective shown and toor toward the position shown in FIG. 15. Conversely, rotating theadjustment screw 404 in a second direction about the adjustment screwaxis 500 that is opposite the first direction may tighten the adjustmentscrew 404 and actuate the collar assembly 400 and the shift collar 310along the axis 70 away from the cover 302. The adjustment screw 404 maybe rotated to axially align the first shift collar gear 334 or secondshift collar gear 336 with a member of the set of drive pinion gears210.

Finally, the locking screw 406 may be tightened to engage the adjustmentscrew 404. For instance, the locking screw 406 may be received in thegap 522 in the head 510 of the adjustment screw 404 to inhibit rotationof the adjustment screw 404 about the adjustment screw axis 500 aspreviously discussed. The actuator 312 may then be subsequently used tomove the shift collar 310 along the axis while the adjuster mechanism318 may remain fixed and moves axially with the collar assembly 400.

It is also contemplated that the adjuster mechanism 318 may be providedto adjust the axial position of a shift collar that is provided with anaxle assembly having any suitable configuration. For instance, theadjuster mechanism 318 may be provided with an axle assembly that doesnot have an electric motor module 26 or that has a transmission modulewith a different configuration, such as a planetary gear configuration.

Operation of the Shift Mechanism

Referring to FIGS. 7-11, the actuator 312 may move the shift collar 310along the axis 70 between a plurality of positions to selectively couplethe shift collar 310 to the transmission 204 or to decouple the shiftcollar 310 from the transmission 204. For instance, the actuator 312 maymove the shift collar 310 along the axis 70 between the first, second,and third positions. Examples of these positions are illustrated inFIGS. 7, 9, and 11. The actuator 312 may also move the shift collar 310along the axis 70 to first and second neutral positions, which are bestshown in FIGS. 8 and 10. It is noted that in FIGS. 7-11 only a portionof the transmission 204 is shown to better illustrate movement of theshift collar 310. It is also noted that the shift collar 310 in FIGS.7-11 includes a first shift collar gear 334 and a second shift collargear 336 unlike the configuration shown in FIGS. 2 and 4, which lacks asecond shift collar gear 336. In the configuration shown in FIGS. 2 and4, the shift collar may move between the same plurality of positions butonly the first shift collar gear 334 may couple the shift collar 310 tothe transmission 204. As a result, the shift collar in FIGS. 2 and 4 mayhave a greater axial length, longer shift distance, longer shift time,and longer standout than the shift collar shown in FIGS. 7-11. In theexamples below, reference to connecting or disconnecting a member of theset of drive pinion gears 210 to/from the drive pinion 30 includesdirect and indirect connections to and disconnections from the drivepinion 30. For instance, a member of the set of drive pinion gears 210may be directly coupled to the drive pinion 30 or indirectly connectedto the drive pinion 30 such as via the drive pinion extension 90.

In FIGS. 7-11, the first shift collar gear 334 and the second shiftcollar gear 336 may be engageable with different members of the set ofdrive pinion gears 210 as will be discussed in more detail below. Thefirst shift collar gear 334 may not connect the set of drive piniongears 210 to the drive pinion 30 when the second shift collar gear 336connects a member of the set of drive pinion gears 210 to the drivepinion 30. Conversely, the second shift collar gear 336 may not connectthe set of drive pinion gears 210 to the drive pinion 30 when the firstshift collar gear 334 connects member of the set of drive pinion gears210 to the drive pinion 30. More specifically, in the configurationshown the first shift collar gear 334 may be engageable with the secondgear 222 or the third gear 224 but not the first gear 220 or the fourthgear 226. The second shift collar gear 336 may be engageable with thefourth gear 226 but not the first gear 220, the second gear 222, or thethird gear 224.

Referring to FIG. 7, the shift collar 310 is shown in the firstposition. In the first position, the shift collar 310 may couple thesecond gear 222 to the drive pinion 30. For example, the teeth of thefirst shift collar gear 334 may mesh with the inner gear teeth 232 ofthe second gear 222. Torque may be transmitted from the rotor 106 to thefirst gear 220 such as via the rotor output flange 130, from the firstgear 220 to the first countershaft gears 270, 270′, from the firstcountershaft gears 270, 270′ to the second countershaft gears 272, 272′via the first and second countershafts 260, 260′, respectively, from thesecond countershaft gears 272, 272′ to the second gear 222, and from thesecond gear 222 to the drive pinion 30 via the first shift collar gear334 of the shift collar 310. The second shift collar gear 336 may notengage the inner gear teeth 234, 236 of the third gear 224 or the fourthgear 226. As such, the first gear 220, the third gear 224, and thefourth gear 226 may be rotatable about the axis 70 with respect to thedrive pinion 30 when the first gear ratio is provided. Torque may beprovided at the first gear ratio in the first position, such as ahigh-speed gear ratio.

Referring to FIG. 8, the shift collar 310 is shown in the first neutralposition. In the first neutral position, the shift collar 310 may notcouple any member of the set of drive pinion gears 210 to the drivepinion 30. As such, the teeth of the first shift collar gear 334 and theteeth of the second shift collar gear 336 may be spaced apart from thefirst gear 220, the second gear 222, the third gear 224, and the fourthgear 226. The teeth of the first shift collar gear 334 may be axiallypositioned between the inner gear teeth 232 of the second gear 222 andthe inner gear teeth 234 of the third gear 224. The teeth of the secondshift collar gear 336 may be axially positioned between the inner gearteeth 234 of the third gear 224 and the inner gear teeth 236 of thefourth gear 226. As such, the first gear 220, the second gear 222, thethird gear 224, and the fourth gear 226 may be rotatable about the axis70 with respect to the drive pinion 30 when the shift collar 310 is inthe first neutral position and torque may not be transmitted between thetransmission 204 and the drive pinion 30. The first neutral position maybe positioned between the first position shown in FIG. 7 and the secondposition shown in FIG. 9.

Referring to FIG. 9, the shift collar 310 is shown in the secondposition. In the second position, the shift collar 310 may couple thethird gear 224 to the drive pinion 30. For example, the teeth of thefirst shift collar gear 334 may mesh with the inner gear teeth 234 ofthe third gear 224. Torque may be transmitted from the rotor 106 to thefirst gear 220 such as via the rotor output flange 130, from the firstgear 220 to the first countershaft gears 270, 270′, from the firstcountershaft gears 270, 270′ to the third countershaft gears 274, 274′via the first and second countershafts 260, 260′, respectively, from thethird countershaft gears 274, 274′ to the third gear 224, and from thethird gear 224 to the drive pinion 30 via the first shift collar gear334 of the shift collar 310. The second shift collar gear 336 may notengage the inner gear teeth 234 of the third gear 224 or the inner gearteeth 236 of the fourth gear 226. As such, the first gear 220, thesecond gear 222, and the fourth gear 226 may be rotatable about the axis70 with respect to the drive pinion 30 when the second gear ratio isprovided. Torque may be provided at the second gear ratio in the secondposition, such as a mid-speed gear ratio.

Referring to FIG. 10, the shift collar 310 is shown in the secondneutral position. In the second neutral position, the shift collar 310may not couple any member of the set of drive pinion gears 210 to thedrive pinion 30. As such, the teeth of the first shift collar gear 334and the teeth of the second shift collar gear 336 may be spaced apartfrom the first gear 220, the second gear 222, the third gear 224, andthe fourth gear 226. The teeth of the first shift collar gear 334 andthe teeth of the second shift collar gear 336 may be axially positionedbetween the inner gear teeth 234 of the third gear 224 and the innergear teeth 236 of the fourth gear 226. As such, the first gear 220, thesecond gear 222, the third gear 224, and the fourth gear 226 may berotatable about the axis 70 with respect to the drive pinion 30 when theshift collar 310 is in the second neutral position and torque may not betransmitted between the transmission 204 and the drive pinion 30. Thesecond neutral position may be positioned between the second positionshown in FIG. 9 and the third position shown in FIG. 11.

Referring to FIG. 11, the shift collar 310 is shown in the thirdposition. In the third position, the shift collar 310 may couple thefourth gear 226 to the drive pinion 30. For example, the teeth of thesecond shift collar gear 336 may mesh with the inner gear teeth 236 ofthe fourth gear 226. Torque may be transmitted from the rotor 106 to thefirst gear 220 such as via the rotor output flange 130, from the firstgear 220 to the first countershaft gears 270, 270′, from the firstcountershaft gears 270, 270′ to the fourth countershaft gears 276, 276′via the first and second countershafts 260, 260′, respectively, from thefourth countershaft gears 276, 276′ to the fourth gear 226, and from thefourth gear 226 to the drive pinion 30 via the second shift collar gear336 of the shift collar 310. The first shift collar gear 334 may notengage the inner gear teeth 232 of the second gear 222 or the inner gearteeth 234 of the third gear 224. As such, the first gear 220, the secondgear 222, and the third gear 224 may be rotatable about the axis 70 withrespect to the drive pinion 30 when the third gear ratio is provided.Torque may be provided at the third gear ratio in the third position,such as a low-speed gear ratio.

The shift collar configuration shown in FIGS. 7-11 may allow a shiftcollar to be provided with a reduced axial length as compared to theconfiguration shown in FIGS. 2 and 4. Moreover, the shift collar maythen have a reduced stroke or actuation distance along the axis 70.Reducing the actuation distance may not only reduce the standout oraxial length of the axle assembly such as along the axis 70, but alsomay reduce the shift time or time to complete a gear shift as shiftcollar gear teeth may be axially positioned closer to the inner gearteeth of a drive pinion gear that is not currently engaged. In addition,the axial length (i.e., length in a direction that extends along theaxis 70) of the teeth of the first shift collar gear 334 may be lessthan the axial length of the teeth of the second shift collar gear 336as the torque that is transmitted via the first shift collar gear 334may be less than the torque transmitted by the second shift collar gear336. Providing a first shift collar gear 334 with teeth having a shorteraxial length may also help reduce the stroke distance of the shiftcollar, shift times, and the standout of the axle assembly. Providingfirst and second shift collar gears with a shift collar may alsodistribute wear between the shift collar gears as opposed to a singleshift collar gear, thereby reducing wear of each shift collar gear. Itis also contemplated that a shift collar may be provided with shiftcollar gears that are only engageable with one drive pinion gear. Forinstance, a third shift collar gear may be provided with the shiftcollar, resulting in first, second, and third shift collar gears thatare engageable with the second, third, and fourth gears.

While exemplary embodiments are described above, it is not intended thatthese embodiments describe all possible forms of the invention. Rather,the words used in the specification are words of description rather thanlimitation, and it is understood that various changes may be madewithout departing from the spirit and scope of the invention.Additionally, the features of various implementing embodiments may becombined to form further embodiments of the invention.

1. A shift mechanism comprising: a shift collar; an actuator; and anadjuster mechanism that includes: a collar assembly that includes: acollar that defines a collar hole that receives the shift collar; and ashift block that is fixedly positioned with respect to the collar, theshift block defining an elongated slot and a first hole that extendsfrom the elongated slot wherein the shift block includes a locking screwhole that receives a locking screw; a follower that is partiallyreceived in the elongated slot and that is operatively connected to theactuator, the follower defining a threaded hole; and an adjustment screwthat is received in the first hole and the threaded hole and that isrotatable about an adjustment screw axis, wherein the adjustment screwhas a threaded portion that is received in the elongated slot and in thethreaded hole in the follower, a head that is disposed adjacent to thefirst hole, and a first shank portion that extends from the head to thethreaded portion and is received in the first hole, wherein rotating theadjustment screw moves the collar assembly and the shift collar along anaxis, and wherein the locking screw inhibits rotation of the adjustmentscrew.
 2. The shift mechanism of claim 1 wherein rotating the adjustmentscrew moves the collar assembly and the shift collar along the axisindependent of the actuator.
 3. The shift mechanism of claim 6 whereinthe adjustment screw has a head that is disposed adjacent to the firsthole and a first shank portion that extends from the head to thethreaded portion and is received in the first hole.
 4. The shiftmechanism of claim 3 wherein the shift block includes a locking screwhole that receives a locking screw that inhibits rotation of theadjustment screw.
 5. The shift mechanism of claim 4 wherein the headincludes a plurality of teeth that extend away from the adjustment screwaxis, and the locking screw is received in a gap between adjacent teethto inhibit rotation of the adjustment screw.
 6. A shift mechanismcomprising: a shift collar; an actuator; and an adjuster mechanism thatincludes: a collar assembly that includes: a collar that defines acollar hole that receives the shift collar; and a shift block that isfixedly positioned with respect to the collar, the shift block definingan elongated slot and a first hole that extends from the elongated slot;a follower that is partially received in the elongated slot and that isoperatively connected to the actuator, the follower defining a threadedhole; and an adjustment screw that is received in the first hole and thethreaded hole and that is rotatable about an adjustment screw axis,wherein the adjustment screw has a threaded portion that is received inthe elongated slot and in the threaded hole in the follower, whereinrotating the adjustment screw moves the collar assembly and the shiftcollar along an axis, and wherein the adjustment screw has a secondshank portion that extends from the threaded portion to an end of theadjustment screw that is disposed opposite the head, wherein the secondshank portion is received in a second hole of the shift block.
 7. Theshift mechanism of claim 6 wherein a retainer is mounted to the secondshank portion to inhibit removal of the adjustment screw from the shiftblock.
 8. The shift mechanism of claim 7 wherein the retainer isdisposed proximate the end of the adjustment screw and is disposedoutside the second hole.
 9. The shift mechanism of claim 1 wherein theshift block includes a second hole that is coaxially disposed with thefirst hole and that extends from the elongated slot, and wherein theadjustment screw is received in the second hole.
 10. The shift mechanismof claim 9 wherein the first hole has a larger diameter than the secondhole and the first hole and the second hole are not threaded.
 11. Theshift mechanism of claim 9 wherein the elongated slot has a major axisthat extends from the first hole to the second hole and a minor axisthat is disposed substantially perpendicular to the major axis, whereinthe major axis has a greater length than the minor axis.
 12. The shiftmechanism of claim 11 wherein the follower has a width that is less thana length of the minor axis.
 13. An axle assembly comprising: a drivepinion that is rotatable about an axis; a transmission that includes aset of drive pinion gears that are spaced apart from the drive pinionand are rotatable about the axis; and a shift mechanism that includes: ashift collar that is rotatable about the axis with the drive pinion andmoveable along the axis with respect to the drive pinion; an actuatorthat is configured to move the shift collar along the axis toselectively connect a member of the set of drive pinion gears to thedrive pinion; and an adjuster mechanism that connects the actuator tothe shift collar, wherein the adjuster mechanism includes: a collarassembly that includes: a collar that defines a collar hole thatreceives the shift collar; and a shift block that is fixedly positionedwith respect to the collar, the shift block defining an elongated slotand a first hole that extends from the elongated slot; a follower thatis partially received in the elongated slot and that is operativelyconnected to the actuator, the follower defining a threaded hole; and anadjustment screw that is received in the first hole and the threadedhole and that is rotatable about an adjustment screw axis, whereinrotating the adjustment screw moves the collar assembly with respect tothe follower, and rotating the adjustment screw moves the collarassembly and the shift collar along the axis independent of theactuator.
 14. The shift mechanism of claim 6 wherein rotating theadjustment screw moves the collar assembly and the shift collar alongthe axis independent of the actuator.
 15. The axle assembly of claim 13wherein the shift mechanism includes a linkage that is coupled to theactuator and a portion of the follower that protrudes from the elongatedslot is received in an opening in the linkage.
 16. The axle assembly ofclaim 15 wherein the shift mechanism includes a detent linkage that isfixedly positioned with respect to the linkage, the detent linkagedefining a recess that is configured to receive a detent feature thatinhibits movement of the linkage and the follower.
 17. The axle assemblyof claim 16 wherein the adjustment screw is rotated when the detentfeature is received in the recess.
 18. The axle assembly of claim 16wherein the linkage and the detent linkage are rotatable about anactuator axis and the linkage is disposed along the actuator axis closerto the actuator than the detent linkage is disposed to the actuator. 19.The axle assembly of claim 13 wherein the collar has a first collar sidethat faces toward the drive pinion and a second collar side that isdisposed opposite the first collar side, wherein a first thrust bearingis disposed between the first collar side and the shift collar and asecond thrust bearing is positioned between the second collar side and aretainer nut that is mounted to the shift collar, wherein the firstthrust bearing and the second thrust bearing facilitate rotation of theshift collar about the axis with respect to the collar assembly.
 20. Theaxle assembly of claim 13 wherein the shift collar has a first end thatfaces toward the drive pinion, a second end that is disposed oppositethe first end, a first tubular shift collar portion that extends fromthe first end toward the second end, and a second tubular shift collarportion that extends from the second end toward the first tubular shiftcollar portion, wherein the first tubular shift collar portion has alarger diameter than the second tubular shift collar portion and thesecond tubular shift collar portion is received in the collar hole.